1. Technical Field
The following description relates to one or more image forming devices that include a belt unit having an endless belt, a plurality of process cartridges, arranged along the belt unit, each of which contains therein a specific color of recording agent used for color image formation, and a detection sensor configured to optically read a detection pattern formed on the endless belt with each recording agent.
2. Related Art
So far, as an image forming device that forms a color image, an image forming device has been known that includes a belt unit having an endless belt and a plurality of process cartridges, arranged along the belt unit, each of which contains therein toner used for color image formation.
The known image forming device has the plurality of process cartridges arranged on a surface of the endless belt in a tandem manner, and each of the process cartridges contains therein toner of a specific one of the colors, black (K), yellow (Y), magenta (M), and cyan (C). Further, the known image forming device forms a color image on a recording medium while sequentially transferring different color toner images in a superimposed manner. Accordingly, in order to assure favorable image quality, the known image forming device needs to control with a high accuracy a position where a toner image is superimposed on another toner image and a density of each toner image.
In consideration of the aforementioned regards, the known image forming device is configured to form a detection pattern with each color of toner on the endless belt and optically detect each detection pattern with an optical sensor which is disposed such that a detection surface thereof faces the surface of the endless belt. Therefore, by reading each detection pattern with the optical sensor, the known image forming device can appropriately correct the position where a toner image is to be superimposed on another toner image and the density of each toner image, and thus form a user-desired image of favorable image quality.